Fixed variable error in wpsc-shipping/usps_20.php

The variable being tested is NOT the one being assigned the new instance of ASHTools().
Escape image links
Update readme.md

Just fixing some weird opensource stuff.
Fix 'also bought' product names and undefined margin var.
Call wpsc_populate_also_bought_list() via 'wpsc_submit_checkout' filter.
Fix SQL IN error in wpsc_populate_also_bought_list().
Tidy up wpsc_also_bought() code and reference correct 'no image' image.
Fun fact: Walk Like an Egyptian was the Number One hit song the year I was born.  For bonus points, how old does that make me?
removing usages of $wpdb where declared but never used
Add filters to allow additional columns on the sales log screen
More filters for purchase logs page
Fix documentation typo in wpsc_find_purchlog_status_name
Check that 'xmlformat' query parameter is set.
Escape enclosure URL in product feed.
Delete FPDF.
Merge pull request #178 from benhuson/origin/delete-fpdf

Delete FPDF files.
Filter gateway checkout form output
Remove name="submit" from checkout page submit buttons
Merge pull request #184 from leewillis77/submit_fix

Remove name="submit" from checkout page submit buttons
Fix warning